Variation of the effective distribution coefficientkeffwith the current densityJin electroepitaxy of semiconductor compounds is analyzed, taking into account the thicknessLof the solution. On the basis of the analytical expression for (keff−k0)/k0derived in this paper, wherek0is the interface distribution coefficient, both the changes in dopant concentration withJand the homogeneous distribution of dopants parallel to the growth direction are explained. It is shown that in electroepitaxy from a limited solution volume (L≲0.1 cm) the difference betweenkeffandk0is negligible even whenJbecomes very high. Thus, we can carry out direct measurements ofk0vsJin order to conduct a quantitative study of dopant incorporation mechanisms.